pimd: use IPPROTO_IP (not SOL_IP) for IP_PKTINFO

Solaris uses the same socket API for IP_PKTINFO as Linux, but doesn't
have a SOL_IP define.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/pimd/pim_ssmpingd.c b/pimd/pim_ssmpingd.c
index 82e0722..d564bf5 100644
--- a/pimd/pim_ssmpingd.c
+++ b/pimd/pim_ssmpingd.c
@@ -110,9 +110,9 @@
   /* Needed to obtain destination address from recvmsg() */
   {
 #if defined(HAVE_IP_PKTINFO)
-    /* Linux IP_PKTINFO */
+    /* Linux and Solaris IP_PKTINFO */
     int opt = 1;
-    if (setsockopt(fd, SOL_IP, IP_PKTINFO, &opt, sizeof(opt))) {
+    if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt))) {
       zlog_warn("%s: could not set IP_PKTINFO on socket fd=%d: errno=%d: %s",
 		__PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
     }